About the same here - I've had one 'restart' while on Facebook and today, a frozen login screen from sleep - had to use the power button and reboot; also, reduced transparency (just did not like the 'see through' effect) and made dark backgrounds in the menu bar & dock. Dave
Have not had to restart the machine at all since the first beta, apart from system updates like 10.10.1. Yosemite has been stable as the rock on my desktop for me.*
*to be fair, I don't have any POP email accounts and haven't had the Wi-Fi problems people have mentioned. I have used this mid-2012 computer in Yosemite as my work/daily/production machine since the GM betas, no issues at all.
The biggest issue I had during the beta-testing phase was that iMovie wouldn't launch (though iDVD, long discontinued, worked perfectly -- what the --), and that during Beta 1 my preferred FTP programs and Safari extensions didn't work. All sorted in due course obviously, that's why they call it a beta.
I'm not meaning to make it sound like Yosemite is without flaw, just passing on my real-world experience with it from the early betas to present. Since I didn't (nor could) test all possible apps and scenarios, there's still plenty of room for problems I continue to be unaware of, but for me and my intensive internet/writing/editing/audio work, it ran so well I was sorely tempted to make it my primary OS by beta 3.